Afterglow is one of many photo editors at the App Store, but an intuitive control layout, tons of subtle effects, and several sharing options make it an interesting option for tweaking your images. The app's primary focus is posting your altered images to Instagram, but you have plenty of other options for sharing as well. Start by taking a picture with your camera or grabbing an image from your photo library.
Rather than dramatic changes, what Afterglow focuses on is perfecting your image with subtle filters and other tweaks. The interface has buttons across the bottom of the screen for basic color tweaks (saturation and contrast, for example), filters, afterglow effects, and basic tools for cropping, rotating, and flipping the image. You also get a revert button in the lower left if you want to discard all your changes.
With the focus on posting the final product to Instagram, images are transformed into perfect squares with subtle filters and real filmlike effects that create the "afterglow." The filters range from black and white variations to color tweaks and mild sepia tone; You're not going to find dramatic filters or textures here like you find in many popular retro filter apps. The afterglow effects give your photo that real film quality, adding colorful lens flares, scratchy film textures, and other effects that give your image a quirky look that seems unintended. Each of the effects have sliders to increase the intensity of the look, but even at 100% the changes are fairly minor.
When you're finished, you can send the photo to your Instagram app for posting, save to your camera roll, send via e-mail, or post to other social networks like Twitter or Facebook. You also have the option to sent it to other supported apps on your iPhone, so if the changes aren't enough, you always have the option to tweak further in apps like PhotoToaster or Camera+.